Pinging under load/ aftermarket intakes manifolds

Hey all. My 5.9 magnum pings under load. I assume it is because the plenum cover is leaking. Its also using some oil and gas mileage has dropped. Since I will have to remove the intake to fix the leak anyways I was thinking of swapping out the keg for an aftermarket one.

Hughes clams their intake to out preform the Mopar ones. Is this true? they also say it will improve the mileage. true?

The Mopar P5007790 intake says it requires modifications to use. what needs to be modified? Can I expect improvements in power and mileage?

I honestly can't think of any modifications needed. But either redneck or Whiteknuckle will chime in, as they both have M1s.

The problem that I see with the M1 is that they are out of production, Mother Mopar isn't making them anymore. So prices will skyrocket and they will become scarce. So get it while you can, because that leaves Hughes and Mr. Hughes apparently is an *******.

I had the opportunity to pick up a good used M1 intake here locally off craigslist late last year. I passed on it, as the owner of the M1 intake stated that he lost a fair bit of low end throttle response with the M1 intake over the stock kegger intake manifold. I decided to perform the kegger mod and install a new plenum gasket, aluminum plate, bolts and washers. Fixing your plenum gasket on your existing intake should cure your pinging issue and help your fuel mileage, too..

that's where im kind of confused. Doesn't the keg have more capacity than the 4 barrel? The pictures ive seen with the plenum cover off looks like its just an open plenum with runners that suck from the open space. Is this inaccurate?